This invention relates to packages for high frequency semiconductor devices and more specifically to housings suitable for protecting Monolithic Microwave Integrated Circuit die (MMICS).
At the present time, much effort and expense is going into research and development relating to MMIC-type galium arsenide circuitry. Chips including this circuitry tend to provide advantages of high speed and high power operation while taking up minimal space. The space reduction can be as much as 50:1 as compared to other methods. These semiconductor chips are not usable for practical applications unless they can be enclosed in and protected by proper packages or housings.
Prior art packages for MMIC semiconductor chips which operate up to or even above 12 gigahertz (GH.sub.z) tend to be expensive and they are generally presently available from only a limited number of suppliers. While some prior art packages allow mounting of MMIC chips within the package in a small area, the packages themselves require excessive amounts of space. This is because some such packages utilize leads that extend beyond the boundaries of the package. These leads often must be tied down to conductors on a substrate surface and then brought from the conductors on the substrate to an adjacent package. This requires that sufficient space be maintained between the prior art packages to facilitate the required electrical and mechanical connections.
Moreover, some prior art packages require that ground plane connection between devices be provided on bottom surfaces of their substrates. This complicates the construction and manufacture of products including such packages. Furthermore, some prior art packages have heat dissipating buttons for removing heat from the chips. Such buttons are difficult to reliably attach to heat sinks. Additionally, some prior art packages have leads which are only suitable for being grounded. The layout of products including such packages is thereby complicated. Furthermore, some prior art packages cost on the order of Fifty Dollars ($50.00) each which makes them unsuitable for many high quantity production items.